Q. Among the following complexes, the one that can exhibit optical activity is
KVPYKVPY 2016Coordination Compounds
Solution:
Optical activity is shown by those complexes, which have optical isomers.
Optical isomers are mirror images that cannot be superimposed on each other. Complexes of type $[M(AA)_{3}]$ and cis $[M(AA)_{2}B]_{2}$ shows optical isomerism. The type of complexes given in the options are as follows:
Complex
Type
$[CoCl_6]^{3-}$
$[MA_6]$
$[Co(en)Cl_4]^-$
$[M(AA)B_4]$
cis $[Co(en)_2Cl_2]^+$
cis $[M(AA)_2B_2]$
trans $[Co(en)_2Cl_2]^+$
trans $[M(AA)_2B_2]$
Thus, cis $[Co(en)_{2}Cl_2 ]^+$ shows optical activity
| Complex | Type |
|---|---|
| $[CoCl_6]^{3-}$ | $[MA_6]$ |
| $[Co(en)Cl_4]^-$ | $[M(AA)B_4]$ |
| cis $[Co(en)_2Cl_2]^+$ | cis $[M(AA)_2B_2]$ |
| trans $[Co(en)_2Cl_2]^+$ | trans $[M(AA)_2B_2]$ |